As mentioned in this thread, it’s common for airlines to retire flight numbers after a major incident. So TWA will never have another flight 800, nor will United ever have a flight 93.
My question: Does this happen across all airlines? Malaysia Airlines will certainly retire #370, but does that mean all the other airlines will retire that number as well?
Also, how “major” does an incident need to be for the flight number to be retired?
I’d say apparently not, since Alaska Airlines has a flight 93 still in operation daily. (SEA to ANC)
TWA doesn’t have any flight numbers anymore because it hasn’t existed since 2001.
Airlines don’t usually cross-retire flight numbers when a competitor’s flight with the same number crashes but maybe they should. Flight 191 was the number for two major U.S. airliner catastrophes just a few years apart - one for Delta and the other for American Airlines.
It isn’t necessarily permanent, either. American eventually reinstated Flight 1, for instance. The marketing value was too good to pass up, after memories of the crash faded.
United accidentally reactivated flights 93 and 175. After a blogger for Time magazine noticed this, it caused a bit of an uproar, forcing United to change its schedules.
The full backstory, for those interested, United had two subsidiaries: Continental and United, that still operate their own planes. However, they both use United callsigns and flight numbers. United gave its Continental subsidiary flight numbers 1-199, 1000-1299, and 1400-1744. The Continental people did not have flight numbers 93 and 175 blocked out, so they just routinely assigned them.